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Glyphis glyphis
Glyphis glyphis (''Speartooth shark)' Kingdom: '''Animalia Phylum: Chordata Class: Chondrichthyes Order: Carcharhiniformes Family: Carcharhinidae Genus: Glyphis Species: Glyphis glyphis Environment: milieu, climate zone, depth range, distribution range: Marine; freshwater; brackish; demersal. Tropical; 5°N - 21°S. Distribution: Western Pacific: northern Australia and New Guinea. Size, weight, age: Max. length: 1 m (male), 1.75 m (female) Short description: Without any known adult specimens, the maximum size of this species has historically been labelled with considerable uncertainty. In 2014, the first known adults were documented and on this basis it reaches a length around 2.6 m (8.5 ft). The speartooth shark has a streamlined, rather robust body with a short, wide head. The snout is flattened, with large nostrils divided into incurrent and excurrent openings by large, triangular flaps of skin. The eyes are small and equipped with nictitating membranes (protective third eyelids). The sizable, arched mouth has very short furrows at the corners. It has 26–29 upper and 27–29 lower tooth rows. The teeth are tall and upright; those in the upper jaw are wide and triangular with serrated edges, while those in the lower jaw are narrow and spear-like with serrations only near the tip, and tiny cusplets at the base in very young individuals. There are five pairs of gill slits, with the first pair longer than the others. The large pectoral fins have strongly convex leading and concave trailing margins, and blunt tips. The pelvic fins are triangular with nearly straight margins. The first dorsal fin originates over the pectoral fin insertions, and is broadly triangular with a narrow apex and a concave trailing margin. The second dorsal fin measures about 67–77% as tall as the first and is similar in shape; there is no midline ridge between the dorsal fins. The anal fin is almost as large as the second dorsal fin and lies slightly behind; it has a deep notch in the posterior margin. The caudal fin is asymmetrical; the lower lobe is narrow and well-developed, while the upper lobe has a gently convex upper margin and a prominent notch in the ventral margin near the tip. The body is covered by small, overlapping oval-shaped dermal denticles bearing three or five horizontal ridges leading to marginal teeth. This species is plain slate-gray above, including the upper surfaces of the pectoral and pelvic fins, and the caudal fin; the underside is white. The boundary between dark and light runs through the bottom rim of the eye, through the gill slits, over the flank well above the pelvic fins, and onto the upper caudal fin lobe. The fins darken towards the posterior margins, forming a black edge on the upper caudal fin lobe; each pectoral fin also has a black blotch underneath, near the tip. The eyes are ringed in white. Biology: Found presumably inshore. Largest whole specimen collected was that of a female with maturity unknown, 175 cm. Large sets of jaws examined indicate that size can attain up to 2 m and possibly 3 m. Viviparous. Biology poorly known. Life cycle and mating behavior: Distinct pairing with embrace. Viviparous, placental. Main reference: Compagno, L.J.V., 1984. FAO Species Catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 2 - Carcharhiniformes. FAO Fish. Synop. 125(4/2):251-655. Rome: FAO IUCN Red List Status: ENDANGERED (''EN)' '''CITES: Not Evaluated CMS: Not Evaluated Threat to humans: Harmless Human uses: Fisheries: of no interest. Category:Carcharhinidae, Sharks